BIO220H1 Lecture Notes - Lecture 19: Population Momentum, The Population Bomb, Logistic Function
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BIO220H1 Full Course Notes
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If rates are constant and if (birth+ immigration) > (death + emigration), growth trajectory is density- independent and exponential growth. But the example that we saw: density-dependent (growth of population is sensitive to the density of population, if density is low, pop grows quickly; if density is high, pop grows slowly, logistic model (inflection point) Allee, the great appes": tried to project what the human pop was at and where it would be (1940s) Assumed pop growth was logistic, assumed it would reach that upper asymptote (carrying capacity) So they thought ~2. 6 billion would be the upper limit of the number of humans that the earth could support. But right now, human pop is 7 billion. ** human pop growth looks more exponential than logistic. Extrapolating from the logistic growth graph gave a poor prediction, why: logistic is not a law, just a hypothesis, logistic assumes r (rate of pop growth: birth control) and k (carrying capacity: technological.
